I'm not sure what you mean by bypassing it with Howell TBI. The TBI has nothing to do with the charcoal canister. If it's not there now it won't be there with the TBI installed.

You will have to run a return line for the TBI, but the return had nothing to do with the canister either. Coming out of the tank in stock condition there would have been a supply line running to the fuel pump, a return line from the fuel filter, and the vapor line to the canister.

The "bypass", since it's vacuum, would be just to cap the line if you weren't going to use the canister. The port Matt's diagram has labeled as Carb is what will connect to your throttle body. The PCV will probably also use this same port, meaning you'll need a T fitting.

The canister is a passive device in these engines. If you block off the hose to the canister, everything will work exactly as before. What the canister does is absorb fumes while parked, and feed them back while running. Since there is no float bowl with the Howell, it has even less to do.